1. Field of Invention
The current invention relates to methods of producing carbon nanotubes, and more particularly to methods of producing carbon nanotubes that have one or more bends, to the carbon nanotubes and products incorporating the carbon nanotubes.
2. Discussion of Related Art
Single walled carbon nanotubes (SWCNTs) have demonstrated immense potential for the utilization of their unique mechanical, chemical, optical and electrical properties (Dekker, C., Phys Today, 22-28, (1999)). The properties of long SWCNTs have been well documented and have resulted in numerous novel devices (Dresselhaus, M. S.; Dresselhaus, G.; Eklund, P. C. Science of Fullerenes and Carbon Nanotubes; Elsevier: San Diego, 1996). Short SWCNTs (<100 nm), however, have not been extensively studied, despite a wide variety of possible applications. At such short lengths, these ballistic one-dimensional conductors become subject to quantum confinement effects. In particular, their electronic structure and their optical properties depend on their length (Sun X., Zaric S., Daranciang D., Welsher K., Lu Y., Li X., and Dai, H., J. Am. Chem. Soc. 130, 6551-6555 (2008)), providing an opportunity to use the length to tune these properties. Ultrashort carbon nanotubes can be obtained by mechanical (Venema, L. C.; Wildoer, J. W. G.; Janssen, J. W.; Tans, S. J.; Tuinstra, H. L. J. T.; Kouwenhoven, L. P.; Dekker, C. Science 283, 52-55 (1999)) or chemical cutting (Gu, Z., Peng, H., Hauge, R. H., Smalley, R. E., and Margrave, J. L., Nano Lett. 2, 1009-1013 (2002)), in combination with standard nanoparticle sorting procedures (Sun X., Zaric S., Daranciang D., Welsher K., Lu Y., Li X., and Dai, H., J. Am. Chem. Soc. 130, 6551-6555 (2008); Huang, X. Y., McLean, R. S., Zheng, M. Anal. Chem. 2005, 77, 6225-6228). These methods yield a relatively sharp distribution of lengths, and the quantum confinement effects have been observed in their optical properties (Sun, et al., J. Am. Chem. Soc. 130, 6551-6555 (2008)). Quantum dot behavior has been demonstrated in carbon nanotubes with natural defects (Postma, H. W. Ch, Teepen, T., Yao, Z., Grifoni, M., Dekker, C., Science 293, 76-79 (2001)) and nanotubes that were intentionally bent using the tip of an atomic force microscope (Bozovic, D., Bockrath, M., Hafner, J. H., Lieber, C. M., Park, H., Tinkham, M., Appl. Phys. Lett. 78, 3693-3695 (2001)). The latter process is time consuming and limited by the size of the tip. Therefore, there is a need for improved methods of producing carbon nanotubes having selectively introduced defects such as bends.